Long slow runs why?

I keep reading about slow runs and doing them at really slow paces, but how does make you faster. I might be wrong and probably am but I run all my runs at what I can comfortably maintain . I am doing the Edinburgh marathon in May and am striving for 3 hr . Never done a marathon before never really run for more than 6 months at any one time. Done 2 races a few years ago a 10k and an half, but then started smoking and did nothing for 2 yrs. Stopped smoking in April and biked and ran on and off since. But now I have signed up for marathon am taking the training more serious. I am upto about 50 miles a week all at 7 ish mins a mile example did a 13.1 mile training run in 1hr33.37secs 7.09 avg. Felt fine afterwards. To me running at what feels comfortable seems the right way, but reading on this furum now not sure.


  • TeknikTeknik ✭✭✭

    Your body needs to adapt physiologically to get you through a marathon - and the theory is those changes to improve endurance only happen at low intensities.  How you measure "low" is debateable, but, as a guide

    1. You can still breathe through the nose (only), or

    2. Heart rate less than 75% max, or

    3. 10% to 15% slower than achievable mara pace (which you don't know yet,  but as a guide, for men, 2.29 x half mara time).

    I checked with some sub 3 Fetch buddies and, up to the last few weeks, their average training pace is around 8mm (which means the long runs are slower than that, as the tempo and MP runs pull the average down).

    These forums are littered with (male) runners who train too fast and blow up at mile 18...feeling fine after 13 miles doesn't mean you'll be fine 10 miles later.image

  • As above - or, in short, because it allows you to build up stamina. No point having speed in a marathon without having the stamina to go with it, you'll get to about 17 miles  (if you're lucky) and stop dead.


  • What are your race times so far? Without that your training pace figures lack context but it sounds to me like you are training too fast.

  • I understand what your saying about how my body needs to adjust to distance. But I am only increasing by 10% a week so my I'm not ramping up to much. My race times are 43 for an hilly 10k and 1hr 41 for an half, but that was a couple of years ago. I am running at just about that for the the 10k but my endurance for the half is a lot better . My last half I injured my calf and should not have run it, so I discount that one. But this is why I am on this site for advise.
  • stutyrstutyr ✭✭✭

    I found the Pfitzinger & Douglas book "Adanced marathoning" very useful at explaining the various sessions that most training schedules are built upon.

    A quick quote from the long run description:

    "balance between running hard enough to simulate the muscle patterns and posture you will use at marathon race pace and running moderately enough that you can recover relatively quickly for your other important training sessions."

    Pfitzinger, Pete; Scott Douglas (2008-12-26). Advanced Marathoning (Kindle Locations 2727-2729). Human Kinetics - A. Kindle Edition.

    If you are saying that you are not feeling any ill-effects from running 13 miles at 7:09 pace, then don't worry about it..  If you are feeling stiff-legged or just a bit tired the next morning, slow down.  As your mileage increases during your marathon training, you may find the accumulating tiredness gets to you and if you don't realise this you are guaranteed an injury.

  • TeknikTeknik ✭✭✭
    Lee. When I said your body needs to adjust, I didn't mean handle the weekly mileage. I meant it needs to change physiologically ie increased capillarisation in slow twitch muscles etc. Such changes only happen at low intensities/ low HR.
  • I've seen plenty of people running long distances at good speeds in training, but it doesnt seem to translate into the times you'd expect on race day.

    I think a lot of people just tire themselves out in training and on race day, they're just too knackered. 

    If you do your long runs - so 20miles plus at basically your race pace - then how can you recover from that in a couple of days to do more training ?

    The plans arent just theoretical  - they do work if you stick to them and use some common sense. 

    Speed work is also essential - but you cant do both at the same time. 

  • I find the long slow Sunday runs invaluable - not only do they increase my stamina, they burn more calories than a shorter, faster run and they give me time and practice at dealing with the psychological side of running.  My brain wants to give up way before my body does and allowing myself to run a longer distance at a slower pace means I can train myself to overcome the 'I just need to walk' voice that usually pops in my head at around 8 or 9 miles - I run without music as I generally run by myself and it's safer to hear what's going on around me.  Also, I practice gel and fluid intakes on these longer runs as you can't tell how your body will react to eating/drinking on a 5 mile run - and you don't (or shouldn't) need it on such a short one anyway.

    On a purely selfish level - the LSR also gives me time to myself to think stuff over and just enjoy running. 

  • Lee - I'm newish to running and l started off running as fast and as long as I could. I was tired all the time and my legs were constantly aching. I then started following a half marathon training plan and my slow runs were at 10:00-10:30 mins. Even though I was training for a half I did LSR up to 20 miles. As I had slowed these runs down I wasnt burning myself out and felt good for the race. I only did a small amount of speed training as well. I set myself a target of 2:00 and finished in 1:47. Therefore, I am a firm believer that training plans, and LSR runs, definitely work

  • 50 miles a week sounds a lot for a fairly new runner. 

  • The tempo and speedwork sessions are where you work on speed.

    The LSRs are where you work on stamina.  If you do these too fast you won't be recovered enough in order to do your hard speedwork sessions properly.

  • Lee, are you doing any 'hard' sessions, as in Interval sessions, or tempo/lactate threshold runs. These can take it out of you, and to do them successfully,  taking things easier on your other runs is often the way to go.

    Different paces or heart rate zones are used to train different aspects of your physiology. As Teknik pointed  out there is a lot going on 'under the bonnet'. I'm no mechanic, but did as I was toldimage churning out easy miles on the long runs, and putting more effort in on one or two speedier sessions per week. This year  as a novice runner I scraped a 1:22 half and 2:59 marathon.

    Even if you don't follow their plans, I found Pfitzinger & Douglas book "Advanced marathoning" really useful in explaining the purpose behind each type of run.

    As has been said, accumulated tiredness can catch up - I didn't recognise this as a novice, and ended up injured and running the marathon not 100% fit.

  • Thanks for all the replies, I will do more research into the effects of each type of run has on the body. I have looked at marathon plans but the one I have does not start till February. That is why I have just been running and increasing millage upto this point of half marathon. I was just going to use this as a base to see improvement and do 10 mile runs for endurance. I have not done any speed work yet, but will after Christmas.
  • When training for my half, I was also running my long runs at my half marathon pace, I didnt' know to run them slower. Now I'm also going to start training for the Edinburgh Marathon (my first one too!)

    Was recently told by a running coach that the long slow runs teach your body to use fat stores for fuel during the marathon, leaving the carbohydrates for when you need them - the 2nd half of the race (6.2 miles image) Your body will become more efficient by training this way, so that when you come to do the marathon, it will know to use the fat first. She also said what has been mentioned above - when you get to the part of your training plan that has your long runs at half mara or greater, you will only end up tiring yourself for the training the following week, requiring more recovery time.

    Good luck with your training, and see you in May!

  • the long slow runs are invaluable for stamina. Make sure you do them or you may find out the hard way why a lot of runners say the real halfway point of a marathon is 20 miles image

    good luck with the training

  • Do you think it's a good idea to leave the garmin at home and just run by feel. With Edinburgh being so far away I'm not going to increase my long run for a couple of months. But I would like to work on speed can any recommend how many times a week I can run full speed. I have a target of under 3 hrs because if I can do this I get a 2014 London place with the Navy running team. So any advice will be appreciated.
  • Depends, if you are like me, I find it hard to run slower than I should, so need the reminder to slow down
  • Hi Lee. I asked the same question at the Asics bootcamp a couple of weeks ago. I've always tried to run my long runs at almost marathon pace, but then obviously struggle the few days after with my runs with tiredness.

    Doing this means your body doesnt get the chance to recover and is continually fatigued (these aren't my words, but what I have remembered the expert saying image)

    I find it really hard to do this though, but after trying it the past 2 weekends, I've found my Garmin has really helped to keep me at a slower pace. So I'd recommend keeping it on.


  • As others have stated, it is all about increasing endurance, without tiring yourself so much that your other runs suffer. It is also about increasing running efficiency. You can not increase your Max Heart rate, but can lower your Min Heart rate, this gives you a larger training range. i.e. If running slow takes less effort, running quicker will also take less effort.

    I am also a big fan of P&D Advanced Marathoning. Even if you don't follow the 18 week schedules they explain the reason and effects of each run.


    I also read the above article prior to each campaign, to remind myself of the 2 types of long run.

  • Smoke,

    I did one to two runs per week that I classed as fast. Tempo (lactate threshold runs), intervals, or a marathon paced session. I do a max of 2 hard sessions per week.

    The book Scooby mentions is really good at explaining the purpose of each type of session, and how it targets different parts of your physiology. Definitely recommended for a sub 3 attempt.

    When I am not bothered about pace, I display heart rate on my Garmin. My long run at the weekend was at 70% mhr - nice and gentle. During marathon training I run slightly harder
  • they say that you take 3 weeks to recover from a marathon/.........if you run your long runs at this pace then you will not ever giove your chance to recover.........I have heard of a the number of people who race 2 or 3 20 milers in training  and then go on to not get the marathon time they were expecting


  • SFL - I'd suggest you go and do a race this weekend.  As with most endeavours - it's impossible to decide upon a realistic destination and make a plan how to get there if you don't know where you are starting from.

    A mistake many runners make is trying to make their training runs simulate exactly what they'll do in the race.  At the end of the day that's the main motivation behind so many people running their long runs much too fast.

  • When you run you use several systems of energy. The Krebs cycle - energy direct from glocose in food eg gels, carb drink, breakfast; The Cori cycle - storing and recycling glycogen using the liver; and from  Lypolysis - the breakdown of fat.

    The problem is you need to get your body used to using all these systems and it uses them in differing ways depending on the speed you are running and how well your body has adapted.

    You can't consume enough glucose to run purely on food - too many gels and drinks would be needed and you can't break them down and absorb them quickly enough anyway. Over a long period the Cori cycle eventually runs out of stored clucose. So the best source is through stored fat (Lypolysis). Running slowly "turns off" the first two processes and tunes your body to run on the stored fat.

  • I used to do exactly what you are doing now and although I wasn't suffering any injuries or felt especially tired, everyone on this forum told me I was asking for trouble.  So rather than waiting for the trouble to arrive, I nipped it in the bud and started to train properly.

    One thing did strike me though, most advocates of the LSR/LSD on this forum talk of a sub 75% heartrate run.  I bought and am using as my training guide now "Advanced Marathoning" by Pete Pfitzinger and Scott Douglas.  They advocate a long run between 74% and 84% of maximal heartrate which can make quite a big difference against sub 75%.  Not everyone has 3 or 4 hours free to run 20 miles at crazy slow paces but that extra 5 or 10% here can make a big difference to the time it takes and the enjoyment you get form it.  They don't advocate really slow runs because your stride pattern will not mimic the one you'll actually be using during the competitive runs and this makes a lot of sense to me.  My LSR runs are slow but a decent enough pace not to frustrate me and average about 80% heartrate.

    I think just as important, if not even more important is you recovery run.  This is done the day after the LSR or a speed session and this run I do, do at very slow pace.  Certainly sub 75%. This makes all the difference as your legs are right as rain the day after.



  • TeknikTeknik ✭✭✭

    Pfitzinger p.19 - the high end is for "elites"; the low end is for us mortals...

  • also for us mortals, there is no recovery run the day after the LSR for P&D lower mileage plans. Pfitz&Douglas reserve that for those running the 70 - 85mpw  and 85+mpw schedules. It's a rest or cross training day for their lower mileage schedules. I take it as a slow recovery row for 40mins.

    Its also great when you do a lot of base work before starting a long training plan, running along at 70ish%HR, to find you are chipping along much quicker then you expected you would be - once that starts happening to you, you get some faith in this long slow run lark.

  • Teknik wrote (see)

    Pfitzinger p.19 - the high end is for "elites"; the low end is for us mortals...

    True but uses the term "generally".  I place my runs roughly in the middle as I don't consider myself a total novice runner and obviously not an elite.  The point about how the stride pattern feels cannot be overlooked.  If it feels abnormal and uncomfortable at sub 75% then the chances are you're going to do yourself more harm than good.  If 80% feel much better and isn't having a negative impact on your body, surely this is what's right for you?

  • TeknikTeknik ✭✭✭

    SB...I've tended to shout from my soapbox having recently converted to low HR training, so apologies if I've sounded too didactic.

    ...just watch you don't drift up too much on the long runsimage

  • smoke free lee wrote (see)
    With Edinburgh being so far away I'm not going to increase my long run for a couple of months.

    No reason why you can't start increasing your long run now. Actually it's a very sensible idea to start early and have a few weeks 'leeway' built in to your long term plan in case of illness or injury. If you're thinking of doing a 16 week training plan, starting it exactly 16 weeks before the marathon leaves no time to make up any training you might miss out on for whatever reason.

    If you get to week 13 and you're still 8 weeks out from the marathon, you can just repeat a few weeks. I don't think this would be anything but good as long as you remember to take it slightly easier every third week.

    Teknik is right about physiological changes your body has to make. The training plans are based on fact and research, they're not just guesswork! The others are right about the forum being littered with first time marathon runners who blow up at 20 miles.

    Train smart and you won't need to train so hard. image

  • Teknik wrote (see)

    SB...I've tended to shout from my soapbox having recently converted to low HR training, so apologies if I've sounded too didactic.

    ...just watch you don't drift up too much on the long runsimage

    Not at all mate, forums are here for exchanging views.

    One thing I do make sure is that i'm very strict on my drift on long runs.  Alarms are triggered if I go over 82% but I'm normally looking at my watch every minute or so to make sure I don't even get that far up in the first place.


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